A hearing aid is provided with several switches for volume control and the like, but a switch provided in the main body is very small, and in many cases, it is difficult to operate the switch in a state where the hearing aid is mounted in the canal. Accordingly, if a user can operate the hearing aid with a gesture (hereinafter, referred to as a hand placement) in which the user of the hearing aid places his/her hand over his/her ear, it becomes easy to operate the hearing aid.
Patent Document 1 describes a device which has a hand placement detection function capable of detecting a hand placement by a distance sensor. If a hand placement is detected, a sound source can be selected when hearing through a headphone.
FIG. 18 is a schematic configuration diagram showing a configuration 1600 which realizes a hand placement detection function described in Patent Document 1. In the configuration shown in FIG. 18, an infrared distance sensor 1611 measures a distance from a contiguous object. As shown in FIG. 18, when the distance δ between the palm 1612 of the users hand and the infrared distance sensor 1611 is within a given range, it is possible to detect the hand placement.
Patent Document 2 describes a device which detects a temporal change in a phase difference spectral pattern using the phase difference spectral pattern input from two microphones changing depending on the ambient situation, without using a distance sensor.
FIG. 19 is a block diagram showing the configuration of a device which detects a temporal change in a phase difference spectral pattern in Patent Document 2. In the arrangement shown in FIG. 19 a phase difference spectrum of two inputs is calculated from input signals from microphones 1901a and 1901b by frequency analysis means 1713a and 1713b and phase difference spectrum calculation means 1714 using fast Fourier transform. Temporal change detection means 1715 detects a time difference in the phase difference spectrum, and in-space change determination means 1716 detects a change in a space based on the detection result of the temporal change detection means 1715.
Patent Document 3 describes a headphone device which detects a users motion for tapping a device casing to perform a predetermined process. The headphone device has electro-acoustic conversion means for reproducing and outputting sound signals, and acousto-electric conversion means provided at a position where reproduced sound can be picked up. With regard to the output of the acousto-electric conversion means, removing means removes sound reproduced from the electro-acoustic conversion means, and determination means determines whether or not a predetermined motion is performed on the casing. When it is determined that a predetermined motion is performed on the casing, control means performs control such that a predetermined process is performed, thereby operating the device without using an operating button or the like.